Immune Health in the Summer
Summertime…a time to lay by the pool, soak up the sunshine (with UV protection of course), take a family vacation, and just enjoy life! Summer offers numerous opportunities to create amazing memories but it is also the season we may tend to overlook when it comes to our immune health. We generally associate cold and flu season with fall and winter so our focus on immune health gets lost as the flowers bloom and the sun shines hotter! However, keeping your immune system functioning at top notch this summer can help set the tone for the whole year. Our Registered Dietitians will walk you through some of their top picks for immune-rich foods to serve this summer - let’s get out those grills, toss some salads and focus on serving up nutrient dense options for our friends, families and neighbors this BBQ season!
RD Top Picks for Summer Immune-Boosting Foods
Eat them in all the colors- red, yellow, orange - and don’t be afraid to snack on them raw or grill them up. Bell peppers are loaded with vitamin C, and in fact are one of the richest sources of vitamin C in our food supply; take that oranges! Vitamin C is a powerful antioxidant and by eating just one bell pepper you can get >150% of your daily recommended intake of vitamin C and let’s be honest - with their sweet taste - it’s not hard to eat an entire pepper (1). Furthermore, have you ever thought about what makes these beautiful veggies so vibrant in color? There are pigments called capsanthin and violaxanthin found in red peppers and yellow peppers respectively that not only give the peppers their color but also pack a powerful disease fighting punch through their antioxidant capabilities (2,3). Antioxidants help prevent disease by neutralizing unstable molecules known as free radicals.
Oranges, kiwi, lemons, limes, and grapefruits are all easy to find in the summer months and like bell peppers are loaded with vitamin C – a powerful antioxidant that can help reduce oxidative stress (4). Free radicals are inevitable – a part of life - but unfortunately these are the nasty little guys that can play a part in leading to chronic disease. Vitamin C is a warrior when it comes to helping defend the body against free radicals and correcting the balance in our bodies. In other words, think of free radicals as the villain and vitamin C as the hero!
Broccoli & Brussels Sprouts
Broccoli and brussels sprouts aren’t often thought of as vitamin C rich foods – as they are often overshadowed by the citrus clan mentioned above but ½ cup of these veggies cooked contains >50% of the daily value for vitamin C1. In addition, there may be something more hiding under these green wonders as research has indicated that diets high in cruciferous vegetables may play a positive role on improving immunity and decreasing risk of diseases such as cancer and heart disease (5,6). Considering they are also high in fiber, vitamin K, folate, vitamin A and potassium, we cannot be totally surprised about all the health benefits they tout! Try these green super-packed veggies steamed, roasted or grilled and drizzled with extra virgin olive oil and lemon.
All the berries- blueberries, strawberries, blackberries, & raspberries are amazing summer immune boosting foods. As with many foods on this list, berries are high in vitamin C but they also contain a host of flavonoids that can contribute large amounts of beneficial antioxidants to our diet. Specifically, blueberries contain anthocyanin – which is not only responsible for putting the “blue” in blueberry but also linked to immune system benefits in the respiratory tract and potentially reducing the occurrence of the common cold (7). Berries are so versatile – added to a smoothie, yogurt or salad or eaten solo- you truly can’t go wrong! We also love to freeze them and add to water or seltzer for a fancy spin on hydration that also tastes delicious.
Putting It All Together
Let’s take this list and make a powerful vitamin C – flavonoid –antioxidant combination by building a spring mix salad topped with thinly sliced red peppers, wedges of mandarin oranges, roasted brussels sprouts and a handful of blueberries all drizzled with a bit of lemon vinaigrette dressing! To support your immune system even further add almonds or pumpkin seeds for their zinc content and salmon and cheese for a boost in vitamin D intake. Serve that chilled at your next summer gathering to nourish you and your guests’ immune systems.
At your next grocery shopping trip here is a fun trick - pick the rainbow! Choose a fruit and/or vegetable in every color - those color pigments are nature’s way of drawing in our attention and giving us a subtle hint that right below the surface is pure goodness. A diet rich in fruits and vegetables this summer is a great way to keep your immune system functioning at its finest…preparing…waiting….ready for the colder weather and unfortunately cold and flu season to return yet again.
Laura Dority MS, RD, LD
- U.S. Department of Agriculture, Agricultural Research Service. FoodData Central, 2019. fdc.nal.usda.gov.
- Kim S, Ha TY, Hwang IK. Analysis, bioavailability, and potential healthy effects of capsanthin, natural red pigment from capsicum spp. Food Reviews International. 2009;25(3):198-213. doi:10.1080/87559120902956141
- Gómez-García M, Ochoa-Alejo N. Biochemistry and molecular biology of carotenoid biosynthesis in chili peppers (capsicum spp..). International Journal of Molecular Sciences. 2013;14(9):19025-19053. doi:10.3390/ijms140919025
- Chambial S, Dwivedi S, Shukla KK, John PJ, Sharma P. Vitamin C in disease prevention and cure: An overview. Indian Journal of Clinical Biochemistry. 2013;28(4):314-328. doi:10.1007/s12291-013-0375-3
- Kapusta-Duch J, Kopec A, Piatkowska E, Borczak B, Leszczynska T. The beneficial effects of Brassica vegetables on human health. Rocz Panstw Zakl Hig. 2012;63(4):389-95.
- RG; MGM. Cruciferous vegetables and cancer prevention. Nutrition and cancer. https://pubmed.ncbi.nlm.nih.gov/12094621/. Accessed April 4, 2022.
- Somerville VS, Braakhuis AJ, Hopkins WG. Effect of flavonoids on upper respiratory tract infections and immune function: A systematic review and meta-analysis. Advances in Nutrition. 2016;7(3):488-497. doi:10.3945/an.115.010538